Physics - Semiconductors Question with Solution | TestHub

When a small amount of impurity atoms is added to a semiconductor (a process called doping), it significantly increases the number of charge carriers (either electrons or holes, depending on the type of impurity).

The conductivity of a semiconductor is given by $\sigma =e(n{\mu }_e+p{\mu }_h)$, where $n$ and $p$ are the concentrations of electrons and holes, respectively. Since doping increases the concentration of charge carriers, the conductivity of the semiconductor increases.

Resistivity $\rho$ is the reciprocal of conductivity ($\rho =\frac{1}{\sigma }$). Therefore, an increase in conductivity results in a decrease in resistivity.

Answer: decreases.